Lexus ES Stalling at Idle

I have an ES too, and those symptoms sound eerily familiar. I had similar issues and it felt like the engine was trying to breathe through a straw. Did you check the fuel pressure itself? A faulty regulator can cause all sorts of havoc.

Fuel pressure was within spec during a static test, but I haven't monitored it dynamically under load. Could a partially failing regulator cause these intermittent issues, even with seemingly normal static pressure?

Absolutely. Think of it like this: a garden hose with a kink. It might seem okay at low flow, but try to water the whole garden at once, and the pressure drops. A dynamic test is crucial; it's the only way to see if the regulator can keep up when the engine demands more fuel. Better take it to a workshop, they are better equipped for this.

Confirmed. Defective fuel pressure regulator. Error code pointed the workshop in the right direction. 45€. Thanks for the advice.